Silicon carbide (SiC) has hitherto been widely used as industrial materials, such as polishing materials (i.e. grinding materials), ceramics sintered bodies, and conductive materials. In particular, silicon carbide has recently attracted attention as a raw material of a single crystal wafer used for a power semiconductor or the like under social backgrounds such as increased energy conservation awareness and expectations for utilization of natural renewable energy resulting from abandonment or reduction of nuclear power generation.
As a method of producing a silicon carbide single crystal, there has been known a sublimation recrystallization method (i.e. modified Lely method) involving sublimating a silicon carbide powder serving as a raw material under a high temperature condition of 2,000° C. or more, to thereby yield a silicon carbide single crystal on a silicon carbide seed crystal.
As the raw material to be used in the sublimation recrystallization method, in Patent Literature 1, there is disclosed a silicon carbide raw material for growing a silicon carbide single crystal, which is a pulverized material of one or both of a silicon carbide single crystal and a silicon carbide poiycrystai grown by the sublimation recrystallization method. The silicon carbide raw material for growing a silicon carbide single crystal is used as a raw material for the second (i.e. next) growth of a silicon carbide single crystal. By conducting the second growth, the concentration of impurities in the silicon carbide single crystal is significantly reduced.
In Patent Literature 2, there is disclosed a silicon carbide powder for producing a silicon carbide single crystal, having an average particle diameter of from 100 μm or more and 700 μm or less and a specific surface area of from 0.05 m2/g or more and 0.30 m2/g or less. The powder exhibits a high and stable sublimation rate in growing the single crystal by the sublimation recrystallization method.